A battery mounted on, for instance, a hybrid motor vehicle or an electric vehicle includes a plurality of battery cells. These battery cells are electrically connected in series by a bus bar to raise an output voltage of, for instance a battery. Then, in order to prevent the overcharge or over-discharge of the battery cells, a temperature sensor for measuring the temperature of the battery cell is attached to the battery.
As a usual temperature sensor attaching structure, for instance, an attaching structure has been known in which a temperature sensor is thermally connected to a battery cell by using a thermally connecting member (see patent literature 1).
Further, an attaching structure has been also known in which a temperature sensor is attached to an upper cover of a battery case for accommodating a plurality of battery cells (see patent literature 2). As shown in FIG. 5, in an upper cover 101 of a battery case, a cylindrical accommodating part 103 for accommodating a temperature sensor 102 is provided and a fastener 104 is provided in the periphery of an opening of the accommodating part 103. Further, in the temperature sensor 102, a clamp 105 engaging with the fastener 104 is provided. The temperature sensor 102 is inserted into the accommodating part 103, and then, the clamp 105 is engaged with the fastener 104 to hold the temperature sensor 102 by the upper cover 101. A bottom of the accommodating part 103 is allowed to come into contact with or close to a battery cell 106 so that the temperature sensor 102 measures the temperature of the bottom of the accommodating part 103.
Further, an attaching structure has been also known in which a battery is provided with a bas bar for electrically mutually connecting a plurality battery cells and a PTC thermistor is attached to a module unit for holding the bas bar (see patent literature 3). In this attaching structure, the PTC thermistor is used not as a temperature measuring element for measuring the temperature of the battery cell, but as an over-current limiting element or a circuit protecting element. Therefore, the PTC thermistor does not come into contact with the battery cell and is soldered to a terminal on a connecting circuit.    [patent literature 1] JP-A-2006-73362    [patent literature 2] JP-A-2005-189080    [patent literature 3] JP-A-2004-95381